Dr P' KIPPELEN

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Respiratory Measurement I LUNG FUNCTION
TESTS PY3002
Dr P. KIPPELEN
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LECTURE OUTLINE

• Tests of ventilatory capacity
• Lung volumes
• Gas exchange
• Exercise tests
• Bronchial provocation tests
• IOC rules for asthma testing in athletes

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FORCED EXPIRATION TEST

• Simplest test
• One of the most informative
• Requires minimal equipment
• Trivial calculations
• Majority of patients with lung disease abnormal
  forced expiration

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THE SPIROMETER

• Old version
• spirometer bell
• kymograph pen

• New version
• portable

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RESPIRATORY MANOEUVRE
? Maximal breath in ? Maximal breath out
?
?
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FEV1 FVC

• Forced expiratory volume in 1 second
• 4.0 L
• Forced vital capacity
• 5.0 L
• usually less than during a slower exhalation
• FEV1/FVC 80

FEV1
FVC
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FLOW-VOLUME CURVE
in HEALTHY subjects
(in L/sec)
(in L)
FVC
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FLOW-VOLUME CURVE
in respiratory patients

• Restrictive disease
• ? expansion of the lung
• e.g., interstitial fibrosis
• Obstructive disease
• ? resistance to airflow
• e.g., COPD, asthma

? FVC
? FEV1
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BRONCHIAL PROVOCATION TESTS

• Exposure of the airways to a stimulus
• allergen
• exercise
• pharmacological bronchoconstrictive agent
• Response of the smooth muscle ?
• baseline FEV1
• post-exposure FEV1
• ? Airway hyperresponsiveness

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EXERCICE TESTING
5
4
Normal subject
3
Drop in FEV1 ? 10 positive test
FEV1 in Litres
2
Asthmatic patient
Spirometry
Exercise
1
8
14
20
0
Time in Minutes
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LUNG VOLUMES

• Values obtained by simple spirometry
• For the others parameters additional
  measurements needed

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LUNG VOLUMES
Dead space
Residual Volume
Tidal volume
Total lung capacity
Expiratory reserve volume
Tidal volume
Vital capacity
Inspiratory reserve volume
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FUNCTIONAL RESIDUAL CAPACITY

• Measured by
• body plethysmography
• helium dilution
• Body plethysmography
• mouthpiece obstructed
• rapid panting
• during inspiration ? pressure of the air in the
  lungs
• air in the box expands slightly
• ? ? pressure in the box

By applying Boyles law (P V constant) ? lung
volume obtained
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FUNCTIONAL RESIDUAL CAPACITY
At beginning After several minutes

• Helium dilution
• Spirometer of known volume and helium
  concentration connected to the patient
• Closed circuit
• Law of conservation of mass

He initial Vs He final (Vs VL)
? Unknown lung volume can be calculated
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RESIDUAL VOLUME
RV FRC - ERV
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INTERPRETATION of RESULTS

• In patients with obstructive diseases
• airway closure occurs at an abnormally high lung
  volume
• ? ? FRC (functional residual capacity)
• ? ? RV (residual volume)
• Patients with reduced lung compliance (e.g.,
  diffuse interstitial fibrosis)
• stiffness of the lungs recoil of the lungs to
  a smaller resting volume
• ? ? FRC
• ? ? RV

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GAS EXHANGE

• ? Blood gases
• most important measurement in the management of
  respiratory failure
• puncture of the radial artery or
• indwelling radial artery catheter
• PaO2
• normal value 95 mmHg (85-100)
• ? with age (85 mmHg at 60)
• ? VA/Q inequality
• Hypoxemia ? in PaO2

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CAUSES OF HYPOXEMIA
Diffusion impairment

• Hypoventilation
• ? alveolar ventilation
• Diffusion impairment
• ? blood-gas barrier thickening
• ? contact time
• Shunt
• VA/Q inequality
• residence at high altitude

O2
Shunt
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BLOOD GASES

• PaCO2
• normal values 37-43 mmHg
• almost unaffected by age
• Cause of ? PaCO2
• hypoventilation
• VA/Q inequality
• ? blood-gas barrier thickening
• ? contact time
• pH
• acidosis
• respiratory acidosis / metabolic acidosis
• alkalosis
• respiratory alkalosis / metabolic alkalosis

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GAS EXHANGE

• ? Diffusing capacity
• of the lungs to CO
• manoeuvre
• vital capacity breath of 0.3 CO 10 helium
• breath holding for 10 sec
• full exhalation
• Why CO ?
• CO taken up by the blood along the capillary
• uptake of CO determined by
• diffusion properties of the blood-gas barrier
  (thickness area)
• rate of combination of CO with blood ? number
  cells in capillaries

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EXERCISE TESTS

• Why exercise ?
• at rest, the normal lung has enormous reserves
  of function
• during exercise, ? reserves
• ? exercise can reveal minor dysfunctions
• to assess disability
• Common variables
• work load
• total ventilation
• respiratory frequency
• tidal volume
• HR

• ECG
• blood pressure
• VO2, VCO2
• arterial PO2, PCO2 and pH

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DYSPNEA

• Sensation of difficulty with breathing
• Demand of ventilation out of proportion to the
  patients ability to respond to that demand
• Inability to adjust CO2 and pH
• Common in
• unfit people
• elderly people
• respiratory patients
• But assessment difficult

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Respiratory Measurement II HOW TO DETECT
ASTHMA IN ATHLETES ? PY3002
Dr P. KIPPELEN
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APPENDIX A OF THE OLYMPIC ANTI-DOPING CODE

• The List of Prohibited Substances and Prohibited
  Methods dated 1st January 2003 states that
• Formoterol,
• Salbutamol,
• Salmeterol,
• Terbutaline
• are Permitted by inhaler only to prevent and/or
  treat asthma and exercise-induced asthma.

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2001 IOC WORKSHOP

• Recent Olympics ?? in the number of athletes
  notifying the need to inhaled a beta2-agonist
  (IBAs)

Games IBAs Athletes
Percent Los Angeles 119 6802
1.7 Atlanta 383
10677 3.6 Nagano 128
2296 5.6 Sydney 607
11087 5.5 NB At Seoul and
Barcelona notification unnecessary. Notifications
from Montreal unavailable
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2001 IOC WORKSHOP

• High prevalence of misdiagnosed asthma/EIB in
  the athletic population (Rundell et al., 2001)
• No scientific evidence to confirm that IBAs ?
  performance
• at pharmacological doses!
• beta2-agonists, when administered systemically,
  do have anabolic effects
• Skewed distribution of notifications of IBAs by
  sport with a higher prevalence in endurance
  sports

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2001 IOC WORKSHOP

• MEDICATION
• - Under-use of inhaled corticosteroids
• - Daily use of IBAs may result in tolerance and
  increased airway reactivity (Inman et al., 1996
  Hancox et al., 1999,2002)

Hancox et al., AJRCCM, 2002
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MAJOR OUTCOME

• Since Salt Lake City (2002) athletes have to
  prove they have got asthma/EIB to be allowed to
  take IBAs
• Which pulmonary function tests can be used ?
• baseline spirometry but (supra)normal values
  usually registered in elite athletes
• response to IBAs 12 FEV1 from baseline
  proof of airway narrowing
• bronchial provocation tests

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BRONCHIAL PROVOCATION TESTS

• Objective
• to detect airway hyperresponsiveness (AHR)
• Direct stimuli
• methacholine
• histamine
• ? only ONE mediator
• Indirect stimuli
• exercise
• hypertonic saline
• eucapnic voluntary hyperventilation
• ? a lot of mediators released

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METHACHOLINE

• Inhalation of increasing doses of a
  pharmacological agent
• Response of the smooth muscle
• Dose or concentration that induce a 20 drop in
  FEV1
• Principal limits
• Non specific for the
• diagnosis of asthma
• (Langdeau et al. 1999)
• Do not exclude EIB

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EXERCISE TESTING

• Methods
• High intensity exercise
• 6-8min duration
• Post-exercise spirometry (3, 5, 7, 10 15min)
• If FEV1 drop ? 10 consistent with EIB
• In the lab
• Choice limited to 2 or 3 ergometers
• Neutral air conditions
• ? False negative tests (Rundell et al. 2000)
• In the field
• Recommended
• But not always feasible
• ? Need surrogate challenges

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HYPERTONIC SALINE

• Hypothesis
• Changes in the osmolarity of the airways
• Cells shrinks
• Release of inflammatory mediators
• Airway narrowing
• Methods
• exposure to a saline solution
• time progressively increased
• FEV1 recorded 1 min after each exposure
• If FEV1 fall ? 15 consistent with asthma
• ? Very messy

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EUCAPNIC VOLUNTARY HYPERVENTILATION

• 6min of hyperpnoea
• dry air
• 4.9 CO2
• 10 fall in FEV1
• Specific for diagnosis of EIA (Rundell et al.
  2004)
• Recommended by the IOC

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IBAs USE SYDNEY vs ATHENS

• SYDNEY 2000 ATHENS 2004
• (notified) (approved)
• NOC IBAs PERCENT IBAs PERCENT
• NZL 31 21.1 11 11.3
• AUS 128 20.7 65 13.7
• UK 62 19.9 62 23.3
• USA 112 18.9 50 9.1
• CAN 55 18.6 11 4.1
• FIN 10 14.3 4 6.6

Anderson et al. submitted
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ASTHMA IN TEAM GB
Dickinson et al., 2005
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CONSEQUENCES OF THE NEW RULE

• Dickinson et al., Thorax, 2005
• ? false positive diagnosis
• 21 of athletes with a previous diagnosis of
  asthma have failed to the demonstrate evidence of
  asthma
• ? false negative diagnosis
• 10 of athletes with no history or previous
  diagnosis of asthma were tested positive
• ? Only athletes who need the medication get it!

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ASTHMA MEDALS IN ATHENS

• 56 athletes met the criteria to use asthma
  medication.
• They won
• - 7 Gold
• - 7 Silver
• 3 Bronze medals
• 13 athletes failed to meet the IOC criteria and
  were subsequently removed from asthma medication
  won
• 2 Gold medals
• ? Asthma and sport not incompatible !!!

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KEY POINTS

• Since Salt Lake City, compulsory for Olympic
  athletes to prove they have got asthma to use
  IBAs
• approval given by a scientific independent panel
  of the IOC-MC
• Recommended tests for the diagnosis of
  asthma/EIA in athletes
• exercise tests
• eucapnic voluntary hyperpnea
• Systematic screening for asthma in elite
  athletes
• ? number of misdiagnosis
• better management of the disease

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FURTHER READING

• BOOKS
• Allergic and respiratory disease in sports
  medicine. Weiler JM. Clinical Allergy and
  Immunology, Marcel Dekker, 1997
• Pulmonary pathophysiology. The essentials. Fifth
  Edition. West JB. Williams Wilkins, 1995
• ORIGINAL PAPERS
• Dickinson JW, et al. Impact of changes in the
  IOC-MC asthma criteria a British perspective.
  Thorax. 2005 Aug60(8)629-32.
• Anderson SD, et al. Responses to bronchial
  challenge submitted for approval to use inhaled
  beta2-agonists before an event at the 2002 Winter
  Olympics. J Allergy Clin Immunol. 2003
  Jan111(1)45-50.
• REVIEWS
• - Anderson SD, Brannan JD. Methods for "indirect"
  challenge tests including exercise, eucapnic
  voluntary hyperpnea, and hypertonic aerosols.
  Clin Rev Allergy Immunol. 2003 Feb24(1)27-54.
• Rundell KW, Jenkinson DM. Exercise-induced
  bronchospasm in the elite athlete. Sports Med.
  200232(9)583-600.